RE: Index clustering factor

From: Orysia Husak <Orysia.Husak_at_apollogrp.edu>
Date: Wed, 23 Jan 2008 13:37:47 -0700
Message-ID: <9EE01EDE55E32A48BC559180056C96910269E2FA@AMSGEV22.apollogrp.edu>


Jonathan,

Thank you for your suggestions! There was indeed column conversion occurring causing the index not to be used.

I appreciate your assistance and love your book. Looking forward to the next one!

Orysia

Orysia Husak
Sr. Oracle DBA - Classroom Applications Hosting University of Phoenix/ Apollo Group, Inc. Office: 602-557-6934
Mobile: 602-377-8586
orysia.husak_at_apollogrp.edu
-----Original Message-----
From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Jonathan Lewis Sent: Thursday, January 10, 2008 12:10 AM To: oracle-l_at_freelists.org
Subject: Re: Index clustering factor

The optimizer cannot ignore the index hint for that query. Therefore the hint is illegal.

The first thing to check is whether you have a column coercion issue. What are the types of the columns and of the input variables - and what does OEM tell you about the run-time predicates ?

Regards

Jonathan Lewis
http://jonathanlewis.wordpress.com

Author: Cost Based Oracle: Fundamentals
http://www.jlcomp.demon.co.uk/cbo_book/ind_book.html

The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html

  • Original Message ----- From: "Orysia Husak" <Orysia.Husak_at_apollogrp.edu> Subject: RE: Index clustering factor

The statement is expected to fetch only 1 or 2 rows. The default Oracle gather_stats generates a histogram size auto.

We've provided an index hint in the SQL and Oracle sill ignores the index.
>
>Our query is :
>
>Select * from tableA where fielda=:A and fieldb=:B
>
>We have an index on tableA (fielda, fieldb), but Oracle isn't using the
index.
>

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Received on Wed Jan 23 2008 - 14:37:47 CST

Original text of this message